VARIABLES IN JAVA

This posts is introduce Types of variables in Java.
Have 03 types of variables:

• Local Variables
• Instance Variables
• Static Variables

1. Instance Variables

Define: Declared Inside class but not inside method

• Examples:

class Test {
   int data = 15; // Instance variable
   float pi = 3.14f; // Instance variable
}

Properties of Instance Variable:

• Instance variable always get a default value: Ex: int data
• Cannot be reinitialized directly within class
  Examples:

class Test {
   int data = 15; 
   data = 20; // Error
}

But is that TRUE if reinit in method

class Test {
   int data = 15;
   void someMethod(){
      data = 20; //allowed
   }
}

2. Static Variables:

detail…to be updated

3. Local Variables

Define: Declared Inside method or method parameters

• Examples:

int areaCircle(int radius) {
   int total = radius * radius;
   return total;
}

Properties of Local Variable:

• Not accessible outside method
• Do not get default value

4. Summary

• Examples:

public class Practice {
    static int staticVariables = 20;
    int instanceVariables = 30;
    void someMethod(){
        int localVariables = 10;
    }

    public static void main(String[] args) {
        Practice obj1 = new Practice();
        System.out.println(obj1.instanceVariables);
        System.out.println(Practice.staticVariables);
    }
}